1. Field
The disclosure relates to a method for determining precisely the aerodynamic moment of resistance of a wheel. This method applies to land transport vehicles.
2. Description of Related Art
It will be recalled that a wheel is defined as being made up of a rim, of a wheel disc and of a tire. The tire, also referred to as the casing, is mounted on the rim to form a wheel.
Regulatory measures of fuel consumption and pollution are currently made on light cars and light utility vehicles in numerous countries. Unfortunately, these measurements do not make it possible to determine precisely the tire contribution to the resistance to forward travel.
It will be recalled that the resistance to forward travel caused by a tire comprises the following three components: the rolling resistance drag (or force), the aerodynamic drag and the aerodynamic moment of resistance (or ventilation torque).
So, in order to calculate or estimate this resistance to forward travel, practitioners take measurements, on a test bed, of the tire mounted simply on the rim, or even resort to simulations using computer software.
However, these measurements or simulations, which are performed on a test bed, do not provide values of the aerodynamic moment of resistance that are close to the values encountered under actual conditions of use of a tire because the current measurement techniques simply estimate the aerodynamic moment of resistance simply by allowing the tire mounted on a rim and arranged in an open environment free of any protection to decelerate.
Physical diameters such as the aerodynamic moment of resistance are, for the time being, the subject of mathematical estimates which despite everything remain unsatisfactory because they are estimated insufficiently.
Thus, a more precise and more realistic measurement of the aerodynamic moment of resistance would allow for a better evaluation of the resistance to forward travel caused by a wheel, and therefore of the impact this has on fuel consumption.
So, there remains a need to be able to have use of a method for determining very precisely, reliably and repeatably, the aerodynamic moment of resistance of a wheel under conditions similar to those of usual conditions of use.